v20251016-0003-Documentation-for-sequence-synchronization.patch

From 2b5b5583f9c733b0d50ec6d2fca26b48aa7449bc Mon Sep 17 00:00:00 2001
From: Vignesh C <vignesh21@gmail.com>
Date: Tue, 7 Oct 2025 20:41:56 +0530
Subject: [PATCH v20251016 3/3] Documentation for sequence synchronization
 feature.

Documentation for sequence synchronization feature.

Author: Vignesh C
Reviewer:  Amit Kapila, Shveta Malik, Dilip Kumar, Peter Smith, Nisha Moond
Discussion: https://www.postgresql.org/message-id/CAA4eK1LC+KJiAkSrpE_NwvNdidw9F2os7GERUeSxSKv71gXysQ@mail.gmail.com
---
 doc/src/sgml/catalogs.sgml                |  30 ++-
 doc/src/sgml/config.sgml                  |  16 +-
 doc/src/sgml/func/func-sequence.sgml      |  24 +++
 doc/src/sgml/logical-replication.sgml     | 239 ++++++++++++++++++++--
 doc/src/sgml/monitoring.sgml              |  14 +-
 doc/src/sgml/ref/alter_subscription.sgml  |  62 +++++-
 doc/src/sgml/ref/create_subscription.sgml |  19 +-
 7 files changed, 359 insertions(+), 45 deletions(-)

diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 51534a6f88c..082444a4d51 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -8199,16 +8199,19 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
   </indexterm>
 
   <para>
-   The catalog <structname>pg_subscription_rel</structname> contains the
-   state for each replicated relation in each subscription.  This is a
-   many-to-many mapping.
+   The catalog <structname>pg_subscription_rel</structname> stores the
+   state of each replicated table and sequence for each subscription.  This
+   is a many-to-many mapping.
   </para>
 
   <para>
-   This catalog contains tables and sequences known to the subscription after running
-   either <link linkend="sql-createsubscription"><command>CREATE SUBSCRIPTION</command></link> or
-   <link linkend="sql-altersubscription"><command>ALTER SUBSCRIPTION ... REFRESH
-   PUBLICATION</command></link>.
+   This catalog contains tables and sequences known to the subscription
+   after running:
+   <link linkend="sql-createsubscription"><command>CREATE SUBSCRIPTION</command></link>,
+   <link linkend="sql-altersubscription-params-refresh-publication">
+   <command>ALTER SUBSCRIPTION ... REFRESH PUBLICATION</command></link>, or
+   <link linkend="sql-altersubscription-params-refresh-sequences">
+   <command>ALTER SUBSCRIPTION ... REFRESH SEQUENCES</command></link>.
   </para>
 
   <table>
@@ -8242,7 +8245,7 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
        (references <link linkend="catalog-pg-class"><structname>pg_class</structname></link>.<structfield>oid</structfield>)
       </para>
       <para>
-       Reference to relation
+       Reference to table or sequence
       </para></entry>
      </row>
 
@@ -8251,12 +8254,21 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
        <structfield>srsubstate</structfield> <type>char</type>
       </para>
       <para>
-       State code:
+       State code for the table or sequence.
+      </para>
+      <para>
+       State codes for tables:
        <literal>i</literal> = initialize,
        <literal>d</literal> = data is being copied,
        <literal>f</literal> = finished table copy,
        <literal>s</literal> = synchronized,
        <literal>r</literal> = ready (normal replication)
+      </para>
+      <para>
+       State codes for sequences:
+       <literal>i</literal> = initialize,
+       <literal>d</literal> = re-synchronize,
+       <literal>r</literal> = ready
       </para></entry>
      </row>
 
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 0a2a8b49fdb..9d54f8b26ed 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -5191,9 +5191,9 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
         is taken into account.
        </para>
        <para>
-        In logical replication, this parameter also limits how often a failing
-        replication apply worker or table synchronization worker will be
-        respawned.
+        In logical replication, this parameter also limits how quickly a
+        failing replication apply worker, table synchronization worker, or
+        sequence synchronization worker will be respawned.
        </para>
       </listitem>
      </varlistentry>
@@ -5334,8 +5334,8 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
       <listitem>
        <para>
         Specifies maximum number of logical replication workers. This includes
-        leader apply workers, parallel apply workers, and table synchronization
-        workers.
+        leader apply workers, parallel apply workers, table synchronization
+        workers and a sequence synchronization worker.
        </para>
        <para>
         Logical replication workers are taken from the pool defined by
@@ -5358,10 +5358,12 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
        <para>
         Maximum number of synchronization workers per subscription. This
         parameter controls the amount of parallelism of the initial data copy
-        during the subscription initialization or when new tables are added.
+        during the subscription initialization or when new tables or sequences
+        are added.
        </para>
        <para>
-        Currently, there can be only one synchronization worker per table.
+        Currently, there can be only one table synchronization worker per table
+        and one sequence synchronization worker to synchronize all sequences.
        </para>
        <para>
         The synchronization workers are taken from the pool defined by
diff --git a/doc/src/sgml/func/func-sequence.sgml b/doc/src/sgml/func/func-sequence.sgml
index e9f5b4e8e6b..80e51e9e365 100644
--- a/doc/src/sgml/func/func-sequence.sgml
+++ b/doc/src/sgml/func/func-sequence.sgml
@@ -143,6 +143,30 @@ SELECT setval('myseq', 42, false);    <lineannotation>Next <function>nextval</fu
         or <literal>SELECT</literal> privilege on the last used sequence.
        </para></entry>
       </row>
+
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_get_sequence_data</primary>
+        </indexterm>
+        <function>pg_get_sequence_data</function> ( <type>regclass</type> )
+        <returnvalue>record</returnvalue>
+        ( <parameter>last_value</parameter> <type>bigint</type>,
+        <parameter>is_called</parameter> <type>bool</type>,
+         <parameter>page_lsn</parameter> <type>pg_lsn</type> )
+       </para>
+       <para>
+        Returns information about the sequence. <literal>last_value</literal>
+        indicates last sequence value set in sequence by nextval or setval,
+        <literal>is_called</literal> indicates whether the sequence has been
+        used, and <literal>page_lsn</literal> is the LSN corresponding to the
+        most recent WAL record that modified this sequence relation.
+       </para>
+       <para>
+        This function requires <literal>USAGE</literal>
+        or <literal>SELECT</literal> privilege on the sequence.
+       </para></entry>
+      </row>
      </tbody>
     </tgroup>
    </table>
diff --git a/doc/src/sgml/logical-replication.sgml b/doc/src/sgml/logical-replication.sgml
index b01f5e998b2..548aab31960 100644
--- a/doc/src/sgml/logical-replication.sgml
+++ b/doc/src/sgml/logical-replication.sgml
@@ -113,7 +113,9 @@
    Publications may currently only contain tables or sequences. Objects must be
    added explicitly, except when a publication is created using
    <literal>FOR TABLES IN SCHEMA</literal>, <literal>FOR ALL TABLES</literal>,
-   or <literal>FOR ALL SEQUENCES</literal>.
+   or <literal>FOR ALL SEQUENCES</literal>. Unlike tables, the current state of
+   sequences may be synchronized at any time. For more information, refer to
+   <xref linkend="logical-replication-sequences"/>.
   </para>
 
   <para>
@@ -1745,6 +1747,209 @@ Publications:
   </note>
  </sect1>
 
+ <sect1 id="logical-replication-sequences">
+  <title>Replicating Sequences</title>
+
+  <para>
+   To synchronize sequences from a publisher to a subscriber, first publish
+   them using <link linkend="sql-createpublication-params-for-all-sequences">
+   <command>CREATE PUBLICATION ... FOR ALL SEQUENCES</command></link> and then
+   at the subscriber side:
+  </para>
+
+  <para>
+   <itemizedlist>
+    <listitem>
+     <para>
+      use <link linkend="sql-createsubscription"><command>CREATE SUBSCRIPTION</command></link>
+      to initially synchronize the published sequences.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      use <link linkend="sql-altersubscription-params-refresh-publication">
+      <command>ALTER SUBSCRIPTION ... REFRESH PUBLICATION</command></link>
+      to synchronize only newly added sequences.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      use <link linkend="sql-altersubscription-params-refresh-sequences">
+      <command>ALTER SUBSCRIPTION ... REFRESH SEQUENCES</command></link>
+      to re-synchronize all sequences.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </para>
+
+  <para>
+   A new <firstterm>sequence synchronization worker</firstterm> will be started
+   after executing any of the above subscriber commands, and will exit once the
+   sequences are synchronized.
+  </para>
+  <para>
+   The ability to launch a sequence synchronization worker is limited by the
+   <link linkend="guc-max-sync-workers-per-subscription">
+   <varname>max_sync_workers_per_subscription</varname></link>
+   configuration.
+  </para>
+
+  <sect2 id="sequence-definition-mismatches">
+   <title>Sequence Definition Mismatches</title>
+   <para>
+    During sequence synchronization, the sequence definitions of the publisher
+    and the subscriber are compared. An ERROR is logged listing all differing
+    sequences before the process exits. The apply worker detects this failure
+    and repeatedly respawns the sequence synchronization worker to continue
+    the synchronization process until all differences are resolved. See also
+    <link linkend="guc-wal-retrieve-retry-interval"><varname>wal_retrieve_retry_interval</varname></link>.
+   </para>
+   <para>
+    To resolve this, use
+    <link linkend="sql-altersequence"><command>ALTER SEQUENCE</command></link>
+    to align the subscriber's sequence parameters with those of the publisher.
+   </para>
+  </sect2>
+
+  <sect2 id="missing-sequences">
+   <title>Missing Sequences</title>
+   <para>
+    During sequence synchronization, if a sequence is dropped on the
+    publisher, the sequence synchronization worker will identify this and
+    remove it from sequence synchronization on the subscriber.
+   </para>
+  </sect2>
+
+  <sect2 id="sequences-out-of-sync">
+   <title>Refreshing Stale Sequences</title>
+   <para>
+    Subscriber side sequence values may frequently become out of sync due to
+    updates on the publisher.
+   </para>
+   <para>
+    To verify, compare the sequence values between the publisher and
+    subscriber, and if necessary, execute
+    <link linkend="sql-altersubscription-params-refresh-sequences">
+    <command>ALTER SUBSCRIPTION ... REFRESH SEQUENCES</command></link>.
+   </para>
+  </sect2>
+
+  <sect2 id="logical-replication-sequences-examples">
+   <title>Examples</title>
+
+   <para>
+    Create some sequences on the publisher.
+<programlisting>
+test_pub=# CREATE SEQUENCE s1 START WITH 10 INCREMENT BY 1;
+CREATE SEQUENCE
+test_pub=# CREATE SEQUENCE s2 START WITH 100 INCREMENT BY 10;
+CREATE SEQUENCE
+</programlisting></para>
+
+   <para>
+    Create the same sequences on the subscriber.
+<programlisting>
+test_sub=# CREATE SEQUENCE s1 START WITH 10 INCREMENT BY 1
+CREATE SEQUENCE
+test_sub=# CREATE SEQUENCE s2 START WITH 100 INCREMENT BY 10;
+CREATE SEQUENCE
+</programlisting></para>
+
+   <para>
+    Update the sequences at the publisher side a few times.
+<programlisting>
+test_pub=# SELECT nextval('s1');
+ nextval
+---------
+      10
+(1 row)
+test_pub=# SELECT nextval('s1');
+ nextval
+---------
+      11
+(1 row)
+test_pub=# SELECT nextval('s2');
+ nextval
+---------
+     100
+(1 row)
+test_pub=# SELECT nextval('s2');
+ nextval
+---------
+     110
+(1 row)
+</programlisting></para>
+
+   <para>
+    Create a publication for the sequences.
+<programlisting>
+test_pub=# CREATE PUBLICATION pub1 FOR ALL SEQUENCES;
+CREATE PUBLICATION
+</programlisting></para>
+
+   <para>
+    Subscribe to the publication.
+<programlisting>
+test_sub=# CREATE SUBSCRIPTION sub1
+test_sub-# CONNECTION 'host=localhost dbname=test_pub application_name=sub1'
+test_sub-# PUBLICATION pub1;
+CREATE SUBSCRIPTION
+</programlisting></para>
+
+   <para>
+    Observe that initial sequence values are synchronized.
+<programlisting>
+test_sub=# SELECT * FROM s1;
+ last_value | log_cnt | is_called
+------------+---------+-----------
+         11 |      31 | t
+(1 row)
+
+test_sub=# SELECT * FROM s2;
+ last_value | log_cnt | is_called
+------------+---------+-----------
+        110 |      31 | t
+(1 row)
+</programlisting></para>
+
+   <para>
+    Update the sequences at the publisher side.
+<programlisting>
+test_pub=# SELECT nextval('s1');
+ nextval
+---------
+      12
+(1 row)
+test_pub=# SELECT nextval('s2');
+ nextval
+---------
+     120
+(1 row)
+</programlisting></para>
+
+   <para>
+    Re-synchronize all the sequences at the subscriber side using
+    <link linkend="sql-altersubscription-params-refresh-sequences">
+    <command>ALTER SUBSCRIPTION ... REFRESH SEQUENCES</command></link>.
+<programlisting>
+test_sub=# ALTER SUBSCRIPTION sub1 REFRESH SEQUENCES;
+ALTER SUBSCRIPTION
+
+test_sub=# SELECT * FROM s1;
+ last_value | log_cnt | is_called
+------------+---------+-----------
+         12 |      30 | t
+(1 row)
+
+test_sub=# SELECT * FROM s2
+ last_value | log_cnt | is_called
+------------+---------+-----------
+        120 |      30 | t
+(1 row)
+</programlisting></para>
+  </sect2>
+ </sect1>
+
  <sect1 id="logical-replication-conflicts">
   <title>Conflicts</title>
 
@@ -2090,16 +2295,19 @@ CONTEXT:  processing remote data for replication origin "pg_16395" during "INSER
 
    <listitem>
     <para>
-     Sequence data is not replicated.  The data in serial or identity columns
-     backed by sequences will of course be replicated as part of the table,
-     but the sequence itself would still show the start value on the
-     subscriber.  If the subscriber is used as a read-only database, then this
-     should typically not be a problem.  If, however, some kind of switchover
-     or failover to the subscriber database is intended, then the sequences
-     would need to be updated to the latest values, either by copying the
-     current data from the publisher (perhaps
-     using <command>pg_dump</command>) or by determining a sufficiently high
-     value from the tables themselves.
+     Incremental sequence changes are not replicated.  Although the data in
+     serial or identity columns backed by sequences will be replicated as part
+     of the table, the sequences themselves do not replicate ongoing changes.
+     On the subscriber, a sequence will retain the last value it synchronized
+     from the publisher. If the subscriber is used as a read-only database,
+     then this should typically not be a problem.  If, however, some kind of
+     switchover or failover to the subscriber database is intended, then the
+     sequences would need to be updated to the latest values, either by
+     executing <link linkend="sql-altersubscription-params-refresh-sequences">
+     <command>ALTER SUBSCRIPTION ... REFRESH SEQUENCES</command></link>
+     or by copying the current data from the publisher (perhaps using
+     <command>pg_dump</command>) or by determining a sufficiently high value
+     from the tables themselves.
     </para>
    </listitem>
 
@@ -2423,8 +2631,8 @@ CONTEXT:  processing remote data for replication origin "pg_16395" during "INSER
    <para>
     <link linkend="guc-max-logical-replication-workers"><varname>max_logical_replication_workers</varname></link>
     must be set to at least the number of subscriptions (for leader apply
-    workers), plus some reserve for the table synchronization workers and
-    parallel apply workers.
+    workers), plus some reserve for the parallel apply workers, table synchronization workers, and a sequence
+    synchronization worker.
    </para>
 
    <para>
@@ -2437,8 +2645,9 @@ CONTEXT:  processing remote data for replication origin "pg_16395" during "INSER
 
    <para>
     <link linkend="guc-max-sync-workers-per-subscription"><varname>max_sync_workers_per_subscription</varname></link>
-     controls the amount of parallelism of the initial data copy during the
-     subscription initialization or when new tables are added.
+     controls how many tables can be synchronized in parallel during
+     subscription initialization or when new tables are added. One additional
+     worker is also needed for sequence synchronization.
    </para>
 
    <para>
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index dc4fc29466d..954ca320331 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -2041,8 +2041,9 @@ description | Waiting for a newly initialized WAL file to reach durable storage
       </para>
       <para>
        Type of the subscription worker process.  Possible types are
-       <literal>apply</literal>, <literal>parallel apply</literal>, and
-       <literal>table synchronization</literal>.
+       <literal>apply</literal>, <literal>parallel apply</literal>,
+       <literal>table synchronization</literal>, and
+       <literal>sequence synchronization</literal>.
       </para></entry>
      </row>
 
@@ -2188,6 +2189,15 @@ description | Waiting for a newly initialized WAL file to reach durable storage
       </para></entry>
      </row>
 
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>sequence_sync_error_count</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times an error occurred during the sequence synchronization
+      </para></entry>
+     </row>
+
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
        <structfield>sync_error_count</structfield> <type>bigint</type>
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 12f72ba3167..d2c9f84699d 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -26,6 +26,7 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> SET PUBLICA
 ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> ADD PUBLICATION <replaceable class="parameter">publication_name</replaceable> [, ...] [ WITH ( <replaceable class="parameter">publication_option</replaceable> [= <replaceable class="parameter">value</replaceable>] [, ... ] ) ]
 ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> DROP PUBLICATION <replaceable class="parameter">publication_name</replaceable> [, ...] [ WITH ( <replaceable class="parameter">publication_option</replaceable> [= <replaceable class="parameter">value</replaceable>] [, ... ] ) ]
 ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> REFRESH PUBLICATION [ WITH ( <replaceable class="parameter">refresh_option</replaceable> [= <replaceable class="parameter">value</replaceable>] [, ... ] ) ]
+ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> REFRESH SEQUENCES
 ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> ENABLE
 ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> DISABLE
 ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> SET ( <replaceable class="parameter">subscription_parameter</replaceable> [= <replaceable class="parameter">value</replaceable>] [, ... ] )
@@ -139,9 +140,9 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
         <term><literal>refresh</literal> (<type>boolean</type>)</term>
         <listitem>
          <para>
-          When false, the command will not try to refresh table information.
-          <literal>REFRESH PUBLICATION</literal> should then be executed separately.
-          The default is <literal>true</literal>.
+          When false, the command will not try to refresh table and sequence
+          information. <literal>REFRESH PUBLICATION</literal> should then be
+          executed separately. The default is <literal>true</literal>.
          </para>
         </listitem>
        </varlistentry>
@@ -158,30 +159,51 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
     <term><literal>REFRESH PUBLICATION</literal></term>
     <listitem>
      <para>
-      Fetch missing table information from publisher.  This will start
+      Fetch missing table information from the publisher.  This will start
       replication of tables that were added to the subscribed-to publications
       since <link linkend="sql-createsubscription">
       <command>CREATE SUBSCRIPTION</command></link> or
       the last invocation of <command>REFRESH PUBLICATION</command>.
      </para>
 
+     <para>
+      Also, fetch missing sequence information from the publisher.
+     </para>
+
+     <para>
+      The system catalog <link linkend="catalog-pg-subscription-rel">pg_subscription_rel</link>
+      is updated to record all tables and sequences known to the subscription,
+      that are still part of the publication.
+     </para>
+
      <para>
       <replaceable>refresh_option</replaceable> specifies additional options for the
-      refresh operation.  The supported options are:
+      refresh operation.  The only supported option is:
 
       <variablelist>
        <varlistentry>
         <term><literal>copy_data</literal> (<type>boolean</type>)</term>
         <listitem>
          <para>
-          Specifies whether to copy pre-existing data in the publications
-          that are being subscribed to when the replication starts.
-          The default is <literal>true</literal>.
+          Specifies whether to copy pre-existing data for tables and synchronize
+          sequences in the publications that are being subscribed to when the replication
+          starts. The default is <literal>true</literal>.
          </para>
          <para>
           Previously subscribed tables are not copied, even if a table's row
           filter <literal>WHERE</literal> clause has since been modified.
          </para>
+         <para>
+          Previously subscribed sequences are not re-synchronized. To do that,
+          see <link linkend="sql-altersubscription-params-refresh-sequences">
+          <command>ALTER SUBSCRIPTION ... REFRESH SEQUENCES</command></link>.
+         </para>
+         <para>
+          See <xref linkend="sequence-definition-mismatches"/> for recommendations on how
+          to handle any warnings about sequence definition differences between
+          the publisher and the subscriber, which might occur when
+          <literal>copy_data = true</literal>.
+         </para>
          <para>
           See <xref linkend="sql-createsubscription-notes"/> for details of
           how <literal>copy_data = true</literal> can interact with the
@@ -200,6 +222,30 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
     </listitem>
    </varlistentry>
 
+   <varlistentry id="sql-altersubscription-params-refresh-sequences">
+    <term><literal>REFRESH SEQUENCES</literal></term>
+    <listitem>
+     <para>
+      Re-synchronize sequence data with the publisher. Unlike
+      <link linkend="sql-altersubscription-params-refresh-publication">
+      <literal>ALTER SUBSCRIPTION ... REFRESH PUBLICATION</literal></link> which
+      only synchronizes newly added sequences, <literal>REFRESH SEQUENCES</literal>
+      will re-synchronize the sequence data for all subscribed sequences. It
+      does not add or remove the missing publication sequences from the
+      subscription.
+     </para>
+     <para>
+      See <xref linkend="sequence-definition-mismatches"/> for
+      recommendations on how to handle any warnings about sequence definition
+      differences between the publisher and the subscriber.
+     </para>
+     <para>
+      See <xref linkend="sequences-out-of-sync"/> for recommendations on how to
+      identify and handle out-of-sync sequences.
+     </para>
+    </listitem>
+   </varlistentry>
+
    <varlistentry id="sql-altersubscription-params-enable">
     <term><literal>ENABLE</literal></term>
     <listitem>
diff --git a/doc/src/sgml/ref/create_subscription.sgml b/doc/src/sgml/ref/create_subscription.sgml
index ed82cf1809e..05bf2f2f49f 100644
--- a/doc/src/sgml/ref/create_subscription.sgml
+++ b/doc/src/sgml/ref/create_subscription.sgml
@@ -228,7 +228,7 @@ CREATE SUBSCRIPTION <replaceable class="parameter">subscription_name</replaceabl
           the initial synchronization requires all data types to have binary
           send and receive functions, otherwise the synchronization will fail
           (see <xref linkend="sql-createtype"/> for more about send/receive
-          functions).
+          functions). This parameter is not applicable for sequences.
          </para>
 
          <para>
@@ -265,6 +265,12 @@ CREATE SUBSCRIPTION <replaceable class="parameter">subscription_name</replaceabl
           <literal>copy_data = true</literal> can interact with the
           <literal>origin</literal> parameter.
          </para>
+         <para>
+          See <xref linkend="sequence-definition-mismatches"/>
+          for recommendations on how to handle any warnings about sequence
+          definition differences between the publisher and the subscriber,
+          which might occur when <literal>copy_data = true</literal>.
+         </para>
         </listitem>
        </varlistentry>
 
@@ -280,6 +286,7 @@ CREATE SUBSCRIPTION <replaceable class="parameter">subscription_name</replaceabl
           temporary files and applied after the transaction is committed. Note
           that if an error happens in a parallel apply worker, the finish LSN
           of the remote transaction might not be reported in the server log.
+          This parameter is not applicable for sequences.
          </para>
 
          <caution>
@@ -310,7 +317,8 @@ CREATE SUBSCRIPTION <replaceable class="parameter">subscription_name</replaceabl
           The value of this parameter overrides the
           <xref linkend="guc-synchronous-commit"/> setting within this
           subscription's apply worker processes.  The default value
-          is <literal>off</literal>.
+          is <literal>off</literal>. This parameter is not applicable for
+          sequences.
          </para>
 
          <para>
@@ -340,7 +348,8 @@ CREATE SUBSCRIPTION <replaceable class="parameter">subscription_name</replaceabl
         <listitem>
          <para>
           Specifies whether two-phase commit is enabled for this subscription.
-          The default is <literal>false</literal>.
+          The default is <literal>false</literal>. This parameter is not
+          applicable for sequences.
          </para>
 
          <para>
@@ -417,6 +426,7 @@ CREATE SUBSCRIPTION <replaceable class="parameter">subscription_name</replaceabl
           changes that don't have an origin. Setting <literal>origin</literal>
           to <literal>any</literal> means that the publisher sends changes
           regardless of their origin. The default is <literal>any</literal>.
+          This parameter is not applicable for sequences.
          </para>
          <para>
           See <xref linkend="sql-createsubscription-notes"/> for details of how
@@ -449,7 +459,8 @@ CREATE SUBSCRIPTION <replaceable class="parameter">subscription_name</replaceabl
           <xref linkend="conflict-update-deleted"/> is enabled, and a physical
           replication slot named <quote><literal>pg_conflict_detection</literal></quote>
           is created on the subscriber to prevent the information for detecting
-          conflicts from being removed.
+          conflicts from being removed. This parameter is not applicable for
+          sequences.
          </para>
 
          <para>
-- 
2.51.0.windows.1